Where does the actual gas exchange happen? a. alveoli
b. bronchi
c. bronchioles
d. cilia

Which element in the third period would you expect to have the larger atomic radius, sodium (na) or sulfur (s)? a. sodium, because it has a higher effective nuclear charge attracting electrons in fewer energy levels. b. sodium, because it has fewer protons attracting electrons in the same energy levels. c. sulfur, because it has more protons attracting electrons in more energy levels. d. sulfur, because it has a higher effective nuclear charge attracting electrons in the same energy levels.

In an oxidation-reduction reaction, oxidation is what happens when a reactant

This classification of drug typically changes the brain's chemistry and reduces its ability to create its own endorphins.